Growth of highly conductive Al-rich AlGaN:Si with low group-III vacancy concentration

Abdullah S. Almogbel*, Christian J. Zollner, Burhan K. Saifaddin, Michael Iza, Jianfeng Wang, Yifan Yao, Michael Wang, Humberto Foronda, Igor Prozheev, Filip Tuomisto, Abdulrahman Albadri, Shuji Nakamura, Steven P. DenBaars, James S. Speck

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

3 Citations (Scopus)
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Abstract

The impact of AlGaN growth conditions on AlGaN:Si resistivity and surface morphology has been investigated using metalorganic chemical vapor deposition. Growth parameters including growth temperature, growth rate, and trimethylindium (TMI) flow have been systematically studied to minimize the resistivity of AlGaN:Si. We observed a strong anticorrelation between AlGaN:Si conductivity and growth temperature, suggesting increased silicon donor compensation at elevated temperatures. Secondary ion mass spectrometry and positron annihilation spectroscopy ruled out compensation by common impurities or group-III monovacancies as a reason for the observed phenomenon, in contrast to theoretical predictions. The underlying reason for AlGaN:Si resistivity dependence on growth temperature is discussed based on the possibility of silicon acting as a DX center in Al0.65Ga0.35N at high growth temperatures. We also show remarkable enhancement of AlGaN:Si conductivity by introducing TMI flow during growth. A minimum resistivity of 7.5 mΩ cm was obtained for n-type Al0.65Ga0.35N, which is among the lowest reported resistivity for this composition.

Original languageEnglish
Article number095119
Number of pages8
JournalAIP ADVANCES
Volume11
Issue number9
DOIs
Publication statusPublished - 1 Sep 2021
MoE publication typeA1 Journal article-refereed

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